[PATCH v11 3/9] usb: chipidea: add otg id switch and vbus connect/disconnect detect

[peter.chen@freescale.com (Peter Chen)]

On Wed, Mar 06, 2013 at 07:09:34PM +0200, Alexander Shishkin wrote:
> > - start/stop API are used at otg id switch and probe routine
> >
> > - Defer some gadget operations at ci's delayed work queue
> 
> When I asked you to reorder patches, I didn't mean squash them all
> into one. Now you have a patch that does 5 different things and none
> of them properly, because you still need to amend these changes later
> in the patchset, like the patch 7, where you remove the delayed work,
> which is added in this patch. At the same time, you have bits in this
> patch that should be moved to other patches. See comments below.
> 

I am sorry to let you review difficult, as I changed/added patch according
to function change, but not updated previous patches.

I will re-organize all patches according to functionalities.
Besides, can you help review all patches during next time, in that case,
I can know which patch is ok.

> 
> You remove this function in patch 7. Why add it in the first place?
> 

As it is needed at patch 7 to let the function work

> > +
> > +static inline void ci_role_destroy(struct ci13xxx *ci)
> > +{
> > +       ci_hdrc_gadget_destroy(ci);
> > +       ci_hdrc_host_destroy(ci);
> > +}
> 
> You shouldn't use "inline" here. And the name of the function is also
> ambiguous, since it destroys all roles. It would be better to just
> call both _destroys(), like I suggested in the diff I gave you some
> time ago.

Will change.

> 
> > +
> >  static ssize_t show_role(struct device *dev, struct device_attribute *attr,
> >                          char *buf)
> >  {
> > @@ -352,25 +468,50 @@ static ssize_t store_role(struct device *dev, struct device_attribute *attr,
> >
> >  static DEVICE_ATTR(role, S_IRUSR | S_IWUSR, show_role, store_role);
> >
> > +static bool ci_is_otg_capable(struct ci13xxx *ci)
> > +{
> > +       return hw_read(ci, CAP_DCCPARAMS, DCCPARAMS_DC | DCCPARAMS_HC)
> > +               == (DCCPARAMS_DC | DCCPARAMS_HC);
> > +}
> 
> Can't we
> a) remember this value so that we don't have to read the register at
> every interrupt

Yes.

> b) also take into account the fact that DCCPARAMS doesn't read
> correctly on all chipideas? (see dr_mode patches)
> 

We have discussed it, but you have not given me exactly answer
"Which situation we can read OTGSC"?

1. We Can't read OTGSC if DCCPARAMS shows it is only device-capable
2. DCCPARAMS doesn't correctly for some chips
3. If we depend on dr_mode, OTGSC should be read when dr_mode = "peripheral",
in that case, the condition is ci->roles[CI_ROLE_GADGET].

If the dr_mode is not set by DT, the 1 and 3 is conflict.


> >
> > -       if (ci->is_otg)
> > +       if (ci_is_otg_capable(ci))
> 
> ci->is_otg is actually the right thing to use, we should instead make
> sure that it's set properly
> 

Yes, what is ci->is_otg stands for in your opinion?
In my patchset, it means it supportes partial OTG (id switch) function.

> >         if (ci->roles[CI_ROLE_HOST] && ci->roles[CI_ROLE_GADGET]) {
> > +               dev_dbg(dev, "support otg\n");
> >                 ci->is_otg = true;
> > +               /* if otg is supported, create struct usb_otg */
> > +               ci_hdrc_otg_init(ci);
> >                 /* ID pin needs 1ms debouce time, we delay 2ms for safe */
> >                 mdelay(2);
> >                 ci->role = ci_otg_role(ci);
> 
> I'm thinking that this should be based on dr_mode patches and not the
> other way around.
> 

No, ci->role means which role is currently.
And it is otg mode already as 
(ci->roles[CI_ROLE_HOST] && ci->roles[CI_ROLE_GADGET]).

> >
> >  static int ci_otg_set_peripheral(struct usb_otg *otg,
> >                 struct usb_gadget *periph)
> > @@ -55,6 +62,7 @@ int ci_hdrc_otg_init(struct ci13xxx *ci)
> >         ci->otg.set_host = ci_otg_set_host;
> >         if (!IS_ERR_OR_NULL(ci->transceiver))
> >                 ci->transceiver->otg = &ci->otg;
> > +       ci_enable_otg_interrupt(ci, OTGSC_IDIE);
> 
> There should be a counter-action to ci_hdrc_otg_init().
> Btw, why can't clear_otg_interrupt() be called from here as well
> instead of hw_device_init()? 

What the criterion for reading OTGSC?
What means otg capable and how do we know it is otg capable?

> This function should only be called for
> otg capable devices, so it should be safe. And while at it, I think
> this whole otg.c/otg.h part of this patch should be moved to patch 2.
> 

OK.

> >
> > +static int udc_id_switch_for_device(struct ci13xxx *ci)
> 
> I would use _to_ instead of _for_, for clarity.
> 
> > +{
> > +       ci_clear_otg_interrupt(ci, OTGSC_BSVIS);
> > +       ci_enable_otg_interrupt(ci, OTGSC_BSVIE);
> > +
> > +       return 0;
> > +}
> > +
> > +static void udc_id_switch_for_host(struct ci13xxx *ci)
> 
> Same here.
> 

Will change

> 
> Newlines are wrong here as well as in the udc.h bit. Which is weird,
> because they were ok in the original patch I sent you
> http://www.mail-archive.com/linux-usb at vger.kernel.org/msg13668.html
> 

Will change

-- 

Best Regards,
Peter Chen